The invention relates to an earthworking implement used with a draft vehicle for working the soil behind the vehicle. More particularly, the invention is a tractor pulled rotary hoe having individually biased hoe wheels for working the soil.
Rotary hoes mounted on the hitch structures of relatively large agricultural tractors work soil behind and laterally of the tractors. Under the same soil conditions, as hard or packed soil, the top layer of soil is not readily worked by the conventional rotary hoes. The soil that is not compacted or hard can be overworked with the conventional rotary hoes. This results in some types of soils being underworked and other soils being overworked.
Zaun in U.S. Pat. No. 3,734,201 discloses a rotary hoe having a tool bar mounted on the three-point hitch of a tractor. Biased arms attached to rotary hoe wheels bias the wheels into the ground. The biasing force on the wheels is substantially the same over the length of the tool bar and is limited to the weight of the tool bar.
Whalen in U.S. Pat. No. 4,194,575 discloses a rotary hoe that is substantially the same as the Zaun rotary hoe. Coil springs associated with each pivoted arm of the hoe function to bias a rotary hoe wheel into the soil. The biasing forces on the rotary hoe wheels along the length of the tool bar are substantially the same and are limited to the weight of the tool bar. The biasing force on each wheel can be varied between 19 to 23 pounds by raising or lowering the tool bar of the rotary hoe.
Earthworking implements have been used with draft vehicles for working the soil behind the drive wheels of the vehicle. These implements have frame structures adapted to be releasably mounted on the hitch of the vehicle. The frame structures are shaped to permit the connection of a tongue of a second implement to the conventional draw bar. Lundin in U.S. Pat. No. 4,195,696 discloses an earthworking implement for working the soil compacted by the heavy wheels of a tractor. The frame of the implement is raised and lowered to change the working depth of the earthworking spring tools.